Currently, coffee manufacturers are making great efforts to optimize brewing systems and offer coffee beans or grinds which are diverse in taste, so as to enable fast and convenient coffee making providing coffee of various tastes. Moreover, many coffee makers have been tested for their coffee tastes and have been certified by authorities. Therefore, the coffee making machines may comprise a logo saying for example “Certified by Italian Tasters”. However, these taste tests are performed under controlled parameters and in practice it is difficult for consumers to obtain the desired coffee taste because coffee makers might be used in various environments with various parameters. This means that a coffee maker might produce coffee with different tastes even if it is used with the same coffee beans.
For example, as one of most important ingredients of coffee, water usually has very different properties in different locations through the world. Moreover, even if it is suggested to brew coffee with pure water or bottled water, many coffee drinkers still trust the quality of tap water and use it to brew coffee. These differences might result in coffee having different tastes.
In addition, although the coffee makers could brew coffee whose taste is recommended or considered as the best by experts, consumers always have their own coffee drinking habits. As a matter of fact, different people usually have different coffee taste preferences. For example, some people would prefer stronger coffee while others prefer milder coffee; some people like stronger coffee in the morning and milder coffee in the afternoon while other people have other preferences. Thus, the same coffee, even if it is highly recommended by experts, cannot satisfy all coffee drinkers.